I've been asked several times independently over the course of last months
for a way to figure out the PID of the user-space process that's holding
a specific GPIO line. This does sound like a valid use-case as the user may
create a background process that requests some lines and then want to kill
it to release those lines.

These patches propose to extend the gpio_v2_line_info struct with the
consumer's PID which is set to the process ID for user-space consumers and
0 for kernel-space ones.

Bartosz Golaszewski (2):
  gpiolib: un-inline gpiod_request_user()
  gpiolib: cdev: export the consumer's PID

 drivers/gpio/gpiolib-cdev.c |  2 ++
 drivers/gpio/gpiolib.c      | 33 +++++++++++++++++++++++++++++----
 drivers/gpio/gpiolib.h      | 14 +++-----------
 include/uapi/linux/gpio.h   |  5 ++++-
 4 files changed, 38 insertions(+), 16 deletions(-)

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2.34.1